Most people own physical gold as a safe secure asset that acts as a hedge and financial insurance in a diversified
portfolio. Gold is less volatile than stocks. It can be volatile in the short term, but is a store of value over the long term. Unlike stocks, gold does not yield anything and is, thus, perceived by some as a non-productive asset to own.
However, what Mark and Owen show you in this book is how you can generate an income from the ETF GLD to help you self-finance your accumulation of physical gold.